Abstract: A piston fuel pump for an internal combustion engine includes a pump cylinder, a pump piston, and a seal. The pump piston is axially displaceable in the pump cylinder. The seal is arranged on a circumference of the pump piston. A radially outer surface of the seal which faces an inner surface of the pump cylinder is configured, in an axial end region, such that the radially outer surface lies against the pump cylinder as the pump piston is at rest relative to the pump cylinder, and such that a relative motion between the pump cylinder and the pump piston in the axial direction causes the seal to lift off from the pump piston in a radially inward direction.

Abstract: A high-pressure fuel pump includes an outlet valve, a valve ball, a valve spring that acts on the valve ball in a closing direction, and a stop body for the valve ball. The stop body has a stop section that limits the opening stroke of the valve ball, and the valve spring is supported by the stop body. The stop body has a cut-out section that at least partially accommodates the valve spring and that has a radial inner periphery which forms a guide for the valve spring.

Abstract: A piston fuel pump for an internal combustion engine includes: a pump cylinder; and a pump piston which is movably accommodated in the pump cylinder. The pump piston is guided radially with the aid of at least a first and at least a second guide section which are spaced axially apart from each other, the first guide section being situated in a pump cylinder of the piston fuel pump, and the second guide section being situated radially outwardly in the area of the end section facing the drive. The piston fuel pump has a supporting and sealing unit for the pump piston on the first guide section, which includes a guidance area for the radial guidance of the pump piston in the pump cylinder and a sealing area having a sealing lip.